## Expected value and variance of probability distribution

Expectation and variance of Prob. Dist
Values of $X$ (Separated by comma ,)
Probabilities $P_x$ (Separated by comma ,)
Results
Expected value of $X$: $E(X)$
Variance of $X$: $\sigma^2$
Standard deviation of $X$: $\sigma$

## Formula

### $V(X) =\sigma^2 = E(X^2) -[E(X)]^2$

where $E(X^2) = \sum_x x^2*P(X=x)$